As a last resort to crashing and performance issues with Safari 5.0, you can downgrade to Safari 4.0.5. Unfortunately, although Apple maintains a Safari 4.0.5 download page, the Safari 4.0.5 installer will not run once Safari 5.0 is present; its states that an older version of Safari cannot be installed over a new one.

To get around this problem, you’ll need to use one of the following options:

Archive and Install Mac OS X Use your Mac OS X installation disc to perform an archive and install process as described here. Install all available updates except for Safari 5.0. Instead, download Safari 4.0.5 from this page if that version is not installed by your Mac OS X disc.

Force install Download Pacifist and the Safari 4.0.5 installer. Drag the Safari 4.0.5 installer package onto the Pacifist application icon to open it. Once the Safari 4.0.5 package is open in Pacifist, select it from the list, then click “Install” in the upper left corner of the Pacifist window. Leave the “use administrator privileges” box checked.

You’ll be presented with a dialog box that states “Application already exists.” Check “Don’t ask again for this installation” then click “Replace.” After performing this process, restart your Mac. You’ll be left with an earlier version of Safari.

Safari 5.0 may exhibit some odd DNS issues that can cause three problems: (1) hangs while loading pages or inordinate slowness; (2) pages do not load on the first try, but load properly on a second try; (3) disruption of a local router’s (wireless or wired) network connection.

“I downloaded Safari 5 andinstalled it last evening. Why is it so slow to open common URLs? I tried clearing the cache and deleting the history. But after opening my regular sites since the clearing, the sites still load very slow. ”

Anecdotal evidence suggests that this issue is caused by a problem with Safari 5.0’s DNS prefetching mechanism, which appears to send more requests than allowed by some ISPs. This issue may also cause problems with some routers.

The fix for both of these issues is generally to switch DNS servers from those generated by your ISP to those offered by OpenDNS. To do so:

Open System Preferences and click “Network”

Select your connection method (AirPort, Ethernet, etc.)

Enter the following items in the “DNS Server” field: 208.67.222.222, 208.67.220.220

Click Apply

Failing the above, other likely remedies of slowness after a Safari update include:

Disable errant plug-ins and add-ons Some plug-ins and add-ons may be incompatible with the new release of Safari, causing performance issues.

In Safari, go to Safari > Preferences in the menu bar. Click the “Security” tab, then deselect “Enable plug-ins.” Restart Safari. If the slowness is gone, a plug-in may be to blame. Look in the folders ~/Library/Internet Plug-Ins and /Library/Internet Plug-Ins and remove the items to a safe location (but don’t delete them). You can then re-enable plug-ins in the “Security tab”, and add the items back one by one, restarting Safari after each, to identify the problem plug-in.

Perform the same process for any items in the following folders:

/Library/Input Methods/

/Library/InputManagers/

~/Library/Input Methods/

~/Library/InputManagers/

One such add-on that has been identified as culpable is CosmoPod, a tool that allows you to download Flash videos and audio content.

To resolve the issue, download the CosmoPod package and launch the installer, then select the “Uninstall” option and follow the steps.

You may also need to uninstall SIMBL by following the same process; download the SIMBL package and run the included uninstaller.

Clear AutoFill and favicons Go to Safari > Preferences and select AutoFill. Click the “Edit” option next to “Other Forms” and remove all of the items.

Next, navigate to ~/Library/Safari and drag the folder “Icons” to the trash, then restart Safari.

Reset Safari Although you’ll lose some potentially valuable stored data, this very simple procedure can resolve the slowness in some cases. Simply go to Safari > Reset Safari (in the Safari menu bar) and check all items.

Some users have reported slow or lagging scrolling in Safari 5.0. In some cases, it appears that this issue is caused by the installation of Flash 10.1, which includes several security fixes but may degrade performance in some regards.

Fix

The fix for this issue is generally to downgrade Flash to the previous iteration (10.0), although this will eliminate a number of important security refinements and other enhancements. As such, you should avoid the downgrade if you can live with the slow scrolling.

A number of users have reported that Safari 5.0 crashes (unexpectedly quits) randomly during regular use. The crashes may occur during page loading, when Safari starts up, when the Mac wakes up from sleep, or when a new page or tab is opened.

Reset Safari Although you’ll lose some potentially valuable stored data, this very simple procedure can resolve the crashing issue in some cases. Simply go to Safari > Reset Safari (in the Safari menu bar) and check all items.

Delete add-ons. Some plug-ins and add-ons may be incompatible with the new release of Safari, causing crashes.

In Safari, go to Safari > Preferences in the menu bar. Click the “Security” tab, then deselect “Enable plug-ins.” Restart Safari. If the slowness is gone, a plug-in may be to blame. Look in the folders ~/Library/Internet Plug-Ins and /Library/Internet Plug-Ins and remove the items. You can then re-enable plug-ins, and add the items back one by one, restarting Safari after each, to identify the problem plug-in.

Perform the same process for any items in the following folders:

/Library/Input Methods/

/Library/InputManagers/

~/Library/Input Methods/

~/Library/InputManagers/

CT Loader has also been known to cause crashes. Delete all of the following files, then restart your Mac and launch Safari.

/Library/Application Support/Conduit

/Library/InputManagers/CTLoader

/Library/Receipts/ctloader.pkg

/Library/Receipts/.pkg

/Library/Application Support/SIMBL/Plugins/CT2285220.bundle

~/Library/Application Support/Conduit

In addition, it appears that APE (Application Enhancer) add-ons may be to blame for at least a portion of the crashes. As such, you may need to temporarily uninstall the APE system completely. Here are the instructions for doing so, from the Unsanity website:

“Prior to version 2.0:

Click on APE Manager or Application Enhancer in System Preferences. Choose the Uninstall option under the Information tab.

Version 2.0 and newer:

Click on Application Enhancer in System Preferences. Click the “Troubleshooting…” button in the About tab. Click the “Uninstall Application Enhancer…” button and follow the instructions.

OR

Download the Application Enhancer installer from unsanity.com/haxies/ape run it and click uninstall.

Some users have reported an issue in which Safari 5.0 renders some web pages with blurry fonts. Apple Discussion poster Peter Whysall writes:

“Since installing Safari 5, I am seeing certain websites where the body text appears to have broken sub-pixel antialiasing. To confuse matters further, this problem can show in text on one part of a page, but not in others.

Peter also posted a screenshot of the problem (Safari on the left — click image to enlarge).

Fix As noted by several users, this problem can be solved by disabling Flash. This can be easily accomplished with ClickToFlash, This handy utility allows users to–as the name implies–trigger playback of Flash content on web pages via a mouse click. It also swaps out Flash-based YouTube videos for higher-quality H.264 versions (something that can also be accomplished by joining the YouTube HTML5 beta).

Failing ClickToFlash, you can download the Flash uninstaller to remove Flash altogether.

I have been in living hell since mid February 2012, trying everything I could think of the get safari working again. It was slow as a pig, hanging and forcing reloads. The spinning beach ball of death was becoming my closest companion, like a bad smell you can’t shake off! So, three weeks into trying everything offered by punters on Mac forums, I found you and decided to try what you recommended, even though the article is almost two years old.

I discovered that the issue was the plugins from the latest version of Flash Player, which updated itself sometime around mid freaking february. What a coincidence.

I simply uninstalled Flash player and went back to the previous version. I’ll deal with any fall out from using an older version when and if it arises. In the mean time, I owe you at least an hour per day… so if you need a testimonial, as they say in the classics, ‘call me’.

Thank you so much, Chris Gibson

PS The jerks at Apple could care less. My next computer will be a PC. At least my expectations of PC are not so high. I bought my daughter a Samsung Laptop for Christmas. It leaves my Mac for dead…